1. Field of the Invention
This invention relates to medical devices, and more particularly to medical devices for securing surgical catheters and the like to a patient""s skin or tissue to prevent dislodgment.
2. Description of the Prior Art
A variety of apparatus used in human and veterinary medicine must be securely attached to a patient, either internally or to the skin. The methods employed for this vary, but excessive time-consumption, unreliability, expense, and risk of injury mar each of them. An apparatus commonly requiring a secure attachment is a catheter. Catheters (tubes, usually composed of plastic) are commonly inserted into blood vessels to administer fluids, medications, or nutrients, to withdraw blood, to measure pressures within the blood vessel or to allow the passage of various instruments through the vessel (such as a pacemaker wire). Catheters may be inserted into a variety of body cavities as well, such as the chest or abdomen. When a simple catheter is inserted into a small peripheral vein (an ordinary intravenous or xe2x80x9cI.V.xe2x80x9d), it is generally secured with adhesive tape to the patient""s skin adjacent the point of insertion. But most other surgical catheters (i.e. those inserted into arteries, major veins, or body cavities, such as the chest or abdomen) must be more reliably secured. Accidental migration to an undesired location or dislodgment of such a catheter can cause bleeding, infection, collapse of a lung, heart rhythm abnormalities, and other potentially fatal complications. Even if no such complication ensues, such accidental migration or dislodgment requires repositioning or replacing the catheter which wastes time and materials and subjects the patient to further risks and additional trauma and punctures.
Several methods have been used to attempt to secure surgical catheters more reliably. Most commonly, a pair of plastic wings, each having an eyelet, are incorporated into the hub of the catheter. The catheter is inserted into the patient, up to the hub. The operator then passes a needle and thread through one of the eyelets, then through the patient""s skin, then ties a knot, cuts the thread and repeats the process on the opposite eyelet.
In some cases the catheter is not designed to be inserted all the way to the hub. Instead it must be inserted to a particular depth determined by the anatomy of a particular patient. In these instances (or in the case of catheters, such as chest tubes, which have no hub) the thread must be cinched tightly around the catheter and sewn through the skin. Alternatively, a catheter-grasping device may be attached anywhere along the length of the catheter. Currently a popular catheter-grasping device consists of two concentric plastic collars, each with a pair of protruding wings, each of which has an eyelet. The inner collar is of pliable plastic and the outer collar is of rigid plastic. After inserting the catheter to the desired depth, the operator slips the inner collar over the protruding portion of the catheter, adjacent the skin. The operator then snaps the outer collar over the inner collar, and then sews the entire assembly in place as described above.
This sewing technique is not entirely reliable-sutures often break, especially if tension must be applied to cinch the catheter. The pressure exerted on the skin both by the sutures and by the apparatus it is securing are highly variable and operator dependent. Too little pressure may result in a loose, floppy attachment which allows the catheter to slide in and out of its insertion site, with the dangerous consequence of introducing germs from the patient""s skin into the bloodstream. Too much pressure may cause skin necrosis and breakdown, which may cause a persistent ulcer, infections, and/or the dislodgment of the catheter.
Moreover, sewing is also tedious and time-consuming, particularly when a catheter grasping device is applied. Many small loose parts must be fumbled with (the needle and thread, and the two parts of the catheter-grasping device), multiplying the chances that one of these parts will be dropped off the sterile field and contaminated. Straight needles are generally provided for this purpose because they eliminate the cost of a curved needle and the instrument to hold it (a needle driver), but as a result the skin must be awkwardly pinched, and the suturing process itself is more traumatic. There is also a risk of penetrating too deeply with the needle, and puncturing a vital structure, or even the catheter itself. These problems occur when attempting to attach this type of catheter-grasping device to a patient who is motionless. When the patient is unable or unwilling to remain motionless long enough for the catheter-grasping device to be attached, this procedure becomes even more difficult and prone to error.
After a catheter has been secured, its position is verified with an x-ray (radiograph). If, as often happens, the catheter is found to be in the wrong position, the time wasted is multiplied, as it is then necessary to undo all the above steps and repeat them. Because catheters of this type are often inserted in emergency situations, time is of the essence. An operator wasting time securing a catheter cannot attend to other pressing matters, and may physically interfere with the access of other health-care personnel to the patient.
But the greatest drawback of sewing a catheter in place is the risk of inadvertent needle-stick injury, a risk which is magnified by the degree to which the operator is rushing to complete an emergency procedure. This risk is also magnified by the straight needle provided by almost every kit manufacturer to save the additional cost of a curved needle and needle-driver. Straight needles require more handling by the operator, and they force the operator to place his/her non-dominant hand in harm""s way because the operator must pinch up the skin to pass the needle through it. Moreover, every needle used in a medical procedure jeopardizes many people besides the operator-nurses, technicians, custodians, and whoever might come into contact with the needle. In recognition of the risk of lethal, incurable blood-borne diseases such as HIV and Hepatitis C, the recently approved federal Needlestick Safety and Prevention Act mandates the use of safer alternatives to conventional needles wherever possible.
Adhesive-backed platforms (for example, U.S. Pat. Nos. 5,855,591 and 5,833,667 to Bierman) have also been proposed as catheter securing devices, but, for lack of reliability, have not found wide acceptance. The manufacturer""s warning with one such device reads as follows: xe2x80x9cCatheter should be sutured to the skin in situations where loss of adherence may occur such as: confused patient, unattended central vascular device, extreme diaphoresis or denuded skin.xe2x80x9d These conditions are very common. For example, even the sickest patients must occasionally be left unattended for short periods. Thus adhesives are unacceptable, even by the standards of their manufacturer, for catheters in which a high degree of security is required. But even if the reliability of adhesives were not in doubt, they suffer from other serious drawbacks. They cannot be used on patients who are very sweaty or have very thin, fragile skin. Yet patients who require a catheter in a major vessel are generally the most ill-a disproportionately large number of them will be very sweaty. Patients who are elderly and/or have chronic illnesses are also among those most likely to need such a catheter. Yet they often have paper-thin skin which will be torn off when the time comes to remove an adhesive. Various solvents are recommended to help remove the adhesive, but these are harsh materials that may themselves damage fragile skin, even if a nurse is patient enough to carry out the tedious and lengthy process of applying them with a cotton-tipped applicator beneath the leading edge of the platform as it is peeled back bit by bit from the skin.
Various straps have been proposed to secure a catheter to a limb, generally involving the use of hook-and-loop closures. None of these has found wide use, even for peripheral venous catheters which do not require a high degree of security. They have no application for central venous catheters which do require a high degree of security, and which, moreover, must generally be affixed to portions of the body which are not conveniently encircled by a strap.
U.S. Pat. No. 5,730,758 to Allgeyer describes a staple and staple applicator for use in skin fixation of catheters, designed to replace the suture placed through the eyelets of existing catheter-grasping devices or hubs. This device requires cumbersome additional equipment (the staple applicator and a staple remover), which is unnecessarily complex because it requires the use of a deforming staple. To allow the use of a stapler without an anvil, the operator must manually pinch the skin so that a fold of skin protrudes up between the opposing points of the staple. The fold of skin so pinched must be precisely located at the proper distance from the eyelet, and neither too wide to fit between the opposing points of the staple, nor too narrow to give adequate purchase for the staple. (Alternatively, to avoid the need for pinching the skin, a still more complex stapler with an anvil would be needed, which Allgeyer does not teach.) The operator must simultaneously carefully align the staple points with the eyelets and the fold of skin. The depth of the staple bite achieved is unpredictable, so that a tenuous attachment may result. If a radiograph subsequently determines that the catheter position must be adjusted, the staples must be removed and discarded, and the patient""s skin must be pierced again with new staples after the adjustment has been made. As with the suturing method discussed above, when the patient is unable or unwilling to remain motionless, the device taught by Allgeyer is even more difficult to use.
Nearly all surgical staples require either that the staple be deformed to apply it, or that a retaining piece be used to receive and hold the barbed end of the staple point. U.S. Pat. No. 5,810,882 to Bolduc et al. reveals a surgical helical fastener which requires neither a means to deform the staple, nor a retaining piece. However, Bolduc teaches the use of the device only within a patient""s body; and more particularly for the purpose of repairing a hernia. Moreover, Bolduc does not teach the use of the device as an integral part of an apparatus-securing device.
Similarly, U.S. Pat. No. 5,540,648 to Yoon discloses an instrument stabilizer with anchoring system for use during endoscopic procedures, in which a number of individual needles are mounted in guides protruding up from the surface of a platform intended for application to an external surface of an anatomical cavity. However, Yoon teaches the use of this stabilizer only during endoscopic procedures, which are brief (a few hours at most), and take place in controlled conditions under anesthesia. The multiple individual needles must be deployed one at a time, which is unsuitably time consuming for application of vascular catheters and many other surgical catheters in which time is of the essence. Furthermore, no mechanism is disclosed for retaining the needles in a deployed position to prevent subsequent dislodgment. Likewise, the Yoon device is unsuitable for use with the many surgical catheters which must remain in place for days or weeks. Yoon further fails to disclose a mechanism to prevent the inadvertent redeployment of a needle after it has been withdrawn, thus creating the risk of contaminated needlestick injury. Yoon also teaches the attachment of an apparatus or cylindrical structure perpendicularly to the surface of the device, in contrast to the need for parallel attachment for most surgical catheters which need to remain in place for a significant length of time, and/or which enter a blood vessel. More importantly, the design of the two types of needles disclosed by Yoon (curved and helical) requires in each case a guide of some sort protruding up from the surface of the stabilizer. While this is suitable for endoscopic procedures in which other equipment will in any case be mounted perpendicular to the surface of the stabilizer, it is highly undesirable for the fixation of surgical apparatus such as vascular catheters, in which a low profile attachment is needed, both for patient comfort and to prevent inadvertent dislodgment of the apparatus.
U.S. Pat. No. 4,164,943 to Hill describes a catheter anchor that employs a number of helical needles protruding from its base. The device is rotated against the skin to screw these needles into the skin. Hill teaches no means for protecting the operator or other personnel from contaminated needlestick injury after the device is withdrawn. Hill further fails to provide a mechanism for preventing the device from rotating in a reverse direction and thus being dislodged inadvertently. If the helical needles employed attack the skin at a low angle, they are likely to lacerate rather than cleanly puncture the skin. Alternatively, if the needles attack at a very high angle, they will need to penetrate to a dangerous depth in order to achieve a secure attachment. The Hill catheter grasping mechanism is bulky, needlessly complex, and it protrudes from the skin to a degree that is undesirable for reasons noted above. It also results in the catheter being secured some height above the skin, whereas the ideal attachment occurs along the shaft of the catheter as close as possible to the point at which it penetrates the skin.
Andersson, et al, disclose in U.S. Pat. No. 4,798,595, an injection device designed to deliver medications to the subcutaneous tissues. Accordingly, Andersson does not involve the use of an anchoring device, and the single needle with which it is fitted does not produce a secure attachment. While Andersson does provide a low profile device after it is fully deployed, it does so only by means of an elaborate and bulky mechanism which must then be removed and discarded. Even if Andersson were to suggest the use of the disclosed device for anchoring functions, and it is submitted that there is no such suggestion, the device would be needlessly expensive and cumbersome. Moreover, no protection against needlestick injury would be provided.
It is an object of the present invention to provide a device for attaching an apparatus to the body which:
(a) can be secured without the use of a needle and with a vastly reduced risk of transmission of blood-borne diseases;
(b) can be secured instantly;
(c) is reliable and secure, with a predictable and optimal degree of pressure against the skin or tissue;
(d) is self-contained and does not require any additional equipment for application or removal;
(e) can be detached from the body instantly and without damage to the skin or tissue;
(f) can be detached from the skin or tissue and reattached in a new position without the use of new equipment;
(g) can be used on any patient regardless of their skin condition, mental state or need for constant monitoring;
(h) reliably and securely grasps a catheter;
(i) can be made to release the catheter for adjustment and then to grasp it again, without being detached from the skin or tissue;
(j) has no loose parts, thus minimizing the chance of dropping a part and thereby contaminating it; and
(k) has a low profile and does not interfere with patient care or patient mobility, or cause undue discomfort to the patient.
It is also desirable to provide a device which is inexpensive to produce, which will work with a wide variety of catheters, and which can easily be employed to anchor other medical apparatus, besides catheters, to a patient""s body.
The present invention is a method and device for securing an apparatus to the body which operates quickly, reliably, and without risk of needle-stick injuries by use of an arcuate anchor, the point of which is pushed out of the device, through the skin or tissue, and back into the device, thus grasping a bite of tissue between the shaft of the anchor and the device.
Other objects and advantages of the present invention will become apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings, wherein like parts in each of the several figures are identified by the same reference numbers.